As one will readily appreciate, the space available for mounting various control devices and their associated circuitry is quite limited in compact and subcompact automobiles. Further, the smaller size engines in such vehicles are more difficult to start and keep running if additional loads are placed on the engine during start and warm-up. In most ignition systems additional loads are electrically disconnected when the ignition key is turned to the start or crank position. When the key is allowed to return to the run position, however, additional loads, for example, air conditioners, rear window deicers, etc., are frequently energized while the engine is struggling thus making it more difficult for the operator to keep the engine running. By way of a specific example, one might consider the circumstances where a compact, air-conditioned vehicle has been driven for some period of time on a hot day with the air conditioner operating for maximum cooling. When the driver stops the vehicle and turns off the ignition switch, the air conditioner is deenergized, however, its control switch which is usually manually operated is often left in the on position. When the operator later restarts the engine and the key moves to the run position, the air conditioner is immediately energized and its load is thrown into the circuitry of the struggling engine as above mentioned.
Thus, the principal motivating objectives which led to the development of the present invention were (a) to provide a simple yet efficient mechanically actuable control device which would replace a plurality of parts such as separate switches, relays, wiring harnesses, etc., which have been characteristic of automotive control circuitry, which device would be particularly adapted for use in subcompact vehicles having limited mounting space; and (b) to provide a manually actuable control device for use in an automotive circuit including the ignition switch, which device, would have typical characteristics of a relay, to wit, it would hold in once its magnetic circuit was completed and automatically drop out when its coil or winding was deenergized, in this particular application by turning off the vehicle ignition switch, but could be selectively, mechanically (in most instances manually) actuated or deactuated by the driver or another occupant of a vehicle.
The fact that the aforesaid objectives have been accomplished through the development of a unique but relatively simple and inexpensive device will be best understood by one who proceeds to a reading of the detailed description of a preferred embodiment of the invention which follows hereinafter. The reader will also become apprised of additional improvements in the art which the invention represents and many will undoubtedly envision applications, other than those above mentioned, in which the invention could readily be used to advantage.